Apparatus for ringless spinning of fibre

ABSTRACT

The apparatus includes a driven spinning bowl with an internal frustoconical inclined surface, the bowl having a base with air vents creating suction within the bowl at rotation of this bowl, whereby separate fibres are drawn along the pipe in the lid of the bowl onto the inclined surface of the bowl and into the trough thereof, where these fibres are collected and a sliver is formed therefrom at rotation of the bowl, which sliver is delivered as a ready yarn through a tube having a portion gradually curving in the direction of delivery of this yarn, this portion being provided with projection to impart a twist to the yarn along the straight portion of this tube, of which the value is greater than the desired value of the twist of the yarn, this greater twist being transmitted to the sliver by means of plates having free ends, the plates being secured on the lid and projecting into the bowl to engage the yarn. The disclosed apparatus enables the portion of the yarn between the trough and the delivery tube to acquire a twist which is greater than the desired twist, which reduces the rate of breakage of the yarn inside the bowl at this portion of the yarn.

United States Patent Khomyakov et al. Apr. 8, 1975 APPARATUS FORRINGLESS SPINNING OF [57] ABSTRACT FIBRE The apparatus includes a drivenspinning bowl with an l inventofsi 3 stepahovich Khomyakov, uiiisllinternal frustoconical inclined surface, the bowl havsovcisktiya 125,231 Albert ing a base with air vents creating suction within theArtumvich Leinek, iiiiistl bowl at rotation of this bowl, wherebyseparate fibres Sovetskaya Ill. 391mb of are drawn along the pipe in thelid of the bowl onto Kostromih the inclined surface of the bowl and intothe trough [22] Filed; Jam 14, 1974 thereof, where these fibres arecollected and a sliver is formed therefrom at rotation of the bowl,which sliver PP 432,827 is delivered as a ready yarn through a tubehaving a portion gradually curving in the direction of delivery 52 us.Cl. 57/58.89 of this Y this P being P with P 51 Int. Cl D0lh 1/12 tionto impart a twist to the yam aiohg the Straight [58] Field of Search57/5839, 58.95 Portion Oithis tube, of which the value is greater thanthe desired value of the twist of the yarn, this greater [56]References'Cited Lwist befi ng trandsmitltled tlo thebsliver by mezciinsof lplatles avin ree en s, t e ates eing secure on t e i UNITEDSTATESPATENTS and p rojecting into the bowl to engage the yarn. The

3.339,:60 9/1967 Mikulccky et al. 57/5889 disclosfid apparatus enablesthe portion of the yam g ni g tween the trough and the delivery tube toacquire a {v /x1990 12/1973 Btiflllng ei 411TII...........IIIII57/524195 twist which is greater thhh the desired twist" wh'ch PrimaryE.\uminer.lohn Petrakes Arm/hey, Agent, or Firm-Fleit & Jacobson Jllbduces the rate of breakage of the yarn inside the bowl at this portionof the yarn.

5 Claims, 4 Drawing Figures PATENTEUAPR 8|975 swan '2 or 2 APPARATUS FORRINGLESS SPINNING OF FIBRE The present invention relates to apparatusfor pneumatic spinning of yarn, and more particularly, to ringlessapparatus for spinning fibre.

The invention may be utilized with utmost effectiveness in obtainingmedium and low count yarn from staple chemical fibre, flax fibre, aswell as from blends of the above fibre with woollen fibre and with oneanother.

There is known an apparatus for ringless spinning of fibre, disclosed inFrench Pat. No. 1,544,444, Int. Cl. D 01 h l/OO, comprising a drivenspinning bowl with an inclined internal surface of a frustoconical shapeand a lid having a suction passage for conveying separated fibres, adelivery passage for delivery of the yarn and a plurality of plates,i.e. intake deflectors, under which there are provided inclinedopenings, these plates and openings being adapted to create an aircushion under the fibres advancing in the suction passage.

This cushion is necessary to ensure that the fibres moving toward theinclined internal surface of the bowl are not arrested by engaging thewall of the suction passage, which engagement may be caused by acentrifugal force resulting from the fibres gradually varying thedirection of their progress.

Both the plates and the openings are inclined in a di rection oppositeto that of rotation of the bowl and coinciding with the direction of theflow of air through the suction passage, and, consequently, with that ofthe motion of the yarn, to raise the effectiveness of the air cushion.The provision of the air cushion improves the conditions of conveyingthe fibres via the suction passage, and, consequently, improves thequality of the yarn produced. However, the known apparatus incorporatesno means for reducing the breakage rate of the yarn, which reduction maybe attained by increasing the value of the twist of the yarn above thedesired twist over the area between the inclined surface of the bowl andthe delivery passage, accomplished by engagement of the plates with theyarn. In the known apparatus this cannot be effected, since the platesare inclined in opposition to the direction of the progress of the yarnand are arranged exclusively the suction passage, which results in anincreased rate of breakage of the yarn.

There is further known an apparatus for ringless spinning of fibres,disclosed in USSR Inventors Certificate No. 213,645, C1. 76 c, 24/01,comprising a driven spinning bowl with an internal inclined surface of afrustoconical shape, the bowl being associated with a lid and having abase with air vents, adapted to create suction within the bowl, to drawseparate fibres a pipe mounted in the lid along the inclined surface ofthe bowl into an annular trough adapted to accummulate therein thefibres and to form from these fibres a thin sliver at rotation of thebowl, this sliver being delivered from the bowl through a funnel-shapedtube.

The end face of this funnel, facing the interior of the bowl, isprovided with an annular shoulder having cut therein a helical threadmatching at a specified angle with a screw thread cut in the internalsurface of the funnel, the thread defining a plurality of ribs adaptedto engage the yarn. The height of the threads of the helical threaddiminishes in the direction of delivery of the yarn, while the height ofthe screw threads increases in the same direction. In this devicetwisting is accomplished over the portions of the yarn, extendingaxially of the bowl, wherefrom this twisting propagates, owing to theelasticity of the yarn. This propagation of the twist is opposed by theso-called twist thresholds in front of which the twist accummulates inthe yarn. The elasticity of the yarn having attained a certain value,the twist in the yarn overcomes the twist threshold and propagatesfurther along the yarn. In the present disclosure the expression a twistthreshold is meant to indicate a local point of resistance to thepropagation of a twist along the yarn.

As a result of the action upon the yarn of several such twist thresholdsthe yarn acquires different values of the twist before a twist thresholdand after it, which might lead to breakage of the yarn at the portionwith a smaller twist. In the foregoing known apparatus such twistthresholds are the point of transition of the yarn from the screw threadupon the helical thread and the annular shoulder, positinnedintermediate of the twist initiation area and the trough. The firstthreshold, i.e. the point of transition from one thread to the other,may be overcome by selecting an appropriate structure of the apparatus,whereas the presence of the other threshold, i.e. of the annularshoulder, leads to the yarn having in the portion thereof between thetrough and the shoulder a smaller value of the twist that the desiredtwist, which may lead to the yarn breaking at this portion. Thistendency may be counteracted by giving the yarn a twist in excess of thedesired value. However, an excessive twist in the yarn rules out its usein the production of a broad range of fabrics (e.g. in production ofknitted fabrics and garments, where yarn with an excessive twist cannotbe employed). The desired value of the twist is meant here to describethe twist corresponding to that acquired by yarn produced by ringspinning frames. The twist value is the number of twists in the yarn perone linear metre of the yarn of the corresponding count, fibrecomposition and a range of fabrics that can be produced from this yarn.

It is an object of the present invention to provide an apparatus forringless of fibre, which would reduce the rate of yarn breakage.

It is an important object of the present invention to provide anapparatus for ringless spinning of fibre, which would ensure productionof yarn with a desired twist.

It is a further object of the present invention to provide an apparatusfor ringless spinning of fibre, which would be of a simple structure.

These and other objects are attained in an apparatus for ringlessspinning of fibre, including a driven spinning bowl having an inclinedinternal surface of a frustoconical shape, the bowl being associatedwith a lid and having a base with air vents adapted to create suctionwithin this bowl, to draw separate fibres from a pipe mounted in the lidalong the inclined internal surface into the annular trough of the bowl,this trough being adapted to accumulate fibres therein and to form athin sliver of these fibres at rotation of the bowl, the sliver beingdelivered as spun yarn through a tube mounted in said lid and havinginternally directed projections for engagement with the yarn, in whichapparatus, in accordance with the present invention, this tube has aportion which is gradually curved in the direction of the delivery ofthe yarn, this portion having said projections positioned thereon, toeffect twisting of the yarn along the straight portion of said tube to adegree that is greater than the desired degree of twisting of this yarn,this greater twist being transmitted to the sliver in the trough of thebowl by means of plates mounted on the lid, the plates having the freeends thereof directed into the bowl, the plates engaging the yarn.

An apparatus with this structure reduces the rate of breakage of theyarn and produces yarn with a desired twist, including the twistpermissible for production of knitted fabrics, owing to the yarn beingimparted a twist over the portion thereof between the trough and thefree end of the plate, which is in excess of the desired value, withsubsequent reduction of this twist to the desired value at the point ofexit of the yarn from the tube. This is attained by the projections onthe curved portion of the tube forming the first twist threshold. Thepositioning of the first twist threshold above the point of twistformation in the straight portion of the yarn opposes propagation of thetwist in the direction of delivery of the yarn, whereby it becomespossible to impart to the yarn in the area of its formation a twist thatis greater than the desired value. The second twist threshold formed bythe end face of the tube is easily overcome by this excessive twist,since the plates engage the yarn at the points of contact, moving to theperiphery of the bowl, which forwards the twist toward the trough,creating the greatest value of the twist adjacentto this bowl, wherebythe twist is effectively transmitted to the sliver laying in the trough.

According to a preferred embodiment of the present invention, it isadvisable that said projections should be presented by a cylindricalcoiled spring having the ends thereof secured to the end faces of thetube. This feature simplifies manufacture of the tube and offers readyreplacement of the spring, as the latter is worn out by the friction ofthe yarn against the limited number of the points of this spring.

To provide for positive forwarding of the twist to the sliver, owing 'topermanent engagement of the plates with the yarn, it is advisable thatthe plates should be arranged on the lid so that the ribs thereofintersect the plane of the trough.

To make for optimum conditions for forwarding the twist to the sliver,it is advisable that the plates should be arranged on the lid so thatthe point of engagement of each plate with the yarn move from the axisof rotation of the yarn toward the periphery thereof in the direction ofrotation of the yarn.

The above conditions may be provided for by the plates being of a spiralshape.

The present invention will be better understood from a detaileddescription of an embodiment thereof with reference to the accompanyingdrawings, wherein:

FIG. 1 is a cross-sectional side view of the herein disclosed apparatusfor ringless spinning of fibre;

FIG. 2 is a view from below of the lid with the plates;

FIG. 3 is a view from below of a different embodiment of the lid withthe plates;

FIG. 4 is a sectional view along line IVIV in FIG. 1.

Referring now to the appended drawings, the apparatus for ringlessspinning of fibre comprises a driven spinning bowl (FIG. 1) having aninternal inclined surface 2 of a frustoconical shape for accumulationthereon of separate fibres 3 being supplied, the base 4 of the bowl 1having made therethrough air vents 5 adapted to create suction withinthis bowl. The bowl 1 includes a trough 6 for accumulation in thistrough of the fibres 3 sliding down the inclined surface 2 of the bowl,which fibres are formed into a thin sliver 7 by rotation of the bowl.The latter is associated with a lid 8 having mounted thereon a tube 9for delivery of spun yarn 10.

Spiral-shaped plates 1 1 have one end thereof secured to the lid 8,while the opposite end 12 (FIG. 2) of each plate is free.

The plates 11 (FIG. 1) are positioned so that their ribs intersect theplane defined by the trough 6 and are held in permanent engagement withthe yarn 10 formed from the sliver 7 in the trough 6 and delivered fromthe bowl 1 via the tube 9 including a straight portion 13 and a smoothlycurved portion 14. The portion 14 includes projections 15 imparting atwist to the yarn 10 over the straight portion 13, this twist being inexcess of the desired twist of the final yarn. This twist is transmittedby means of the plates 11 to the sliver 7. The projections 15 arearranged with a pitch ensuring that the yarn is so supported by theseprojections that it would not contact the walls of the tube 9.

The direction of the projections should correspond to the direction ofthe twisting of the yarn. The projections 15 may be formed by anextended cylindrical coiled spring 16 with a corresponding direction ofthe coils, tightly fitting into the tube 9. In this case the oppositeends of the spring 16 are secured to the respective end faces of thetube 9.

The plates 11 (FIG. 2) are positioned so that the point A of contact ofeach one of the plates with the yarn 10 moves away from the axis ofrotation of the bowl 1 toward the periphery of the bowl in the directionof delivery of the yarn, which corresponds to the direction of rotationof the bowl indicated in the drawing with the arrow B. The plates 11 mayalternatively be in the form of a pair of spirals 17, as is shown inFIG. 3, or even in the form of a single spiral, as is shown in FIG. 4.

The lid 8 (FIG. 1) has mounted thereon a pipe 19 through which separatefibres 3 are conveyed in a stream of air into the bowl 1 under theaction of suction created in this bowl, onto the inclined surface 2 ofthe bowl. Separation of the fibres 3 and delivery of the final yarn 10are effected in any suitable known manner.

The spinning bowl is mounted on a spindle 20 designed for rotation inbearings 21 and receiving rotation from any suitable known drivemechanism not shown in the drawings.

The spinning bowl 1 is enclosed within a casing 22 provided with anexhaust connection 23 sealingly connected in any known suitable mannerwith a manifold through which air coming into the bowl 1 is withdrawntherefrom. The direction of supply of the fibres into the bowl isindicated in the drawings with the reference arrow C, while thedirection of delivery of the yarn is indicated with the arrow D.

The apparatus operates as follows.

The spindle 20 is rotated by the drive mechanism (not shown) jointlywith the bowl 1. The air vents 5 create suction within the bowl 1, whichresults in a stream of air being drawn into the bowl 1 via the pipe 19,the stream carrying separate fibres 3 therealong and placing them ontothe inclined surface 2. Upon having engaged this inclined surface 2, thefibres 3 vary the direction of their advance and are pressed in astraightened form to this surface by the centrifugal force. The actionof the same centrifugal force makes the fibres 3 slide down the inclinedsurface 2 of the frustoconical shape, and, while so sliding from asmaller diameter of the bowl toward a greater one, they are straightenedeven further and accummulate in the trough 6, in the form of a thinsliver 7.

Simultaneously with the commencing of feeding of the separate fibres 3,an end of the already spun yarn is introduced into the tube 9. Theaction of suction within the bowl 9 creates a stream of air via the tube9, directed into the bowl 1. This stream flows along said end of thealready spun yarn 10, into the internal space of the bowl 1, where thisend is taken by the rotating stream of air, and the rotating end of theyarn 10 engages the sliver 7 in the trough 6. This rotating end of theyarn winds the sliver 7 thereabout, in which way the spinning operationcommences. Then the spun yarn 10 is withdrawn from the bowl continuouslyby any suitable known mechanism (not shown) in the direction indicatedwith the arrow D.

The portion of the yarn 10 between the trough 6 and the tube 9, which isrotating at an angular speed approximating the angular speed of rotationof the bowl 1, imparts a twist to the portion of the yarn in thestraight portion 13 of the tube 9. The curving portion 14 of the tube 9includes the projections 15 which the yarn 10 engages, owing to thetension thereof caused by the action of the centrifugal force created atthe rotating portion of the yarn 10 between the trough 6 and the tube 9.

At each point of engagement of the tensioned yarn 10 with the projection15 there is created a twist threshold opposing propagation of the twistin the direction of delivery of the yarn. The direction of inclinationof the projections 15 coincides with the direction of twisting of theyarn 10, whereby the yarn engaging the projections and slidingtherealong is acted upon by forces of friction of which thecorresponding components create a torque tending to impart to the yarn afalse twist in a direction opposite to that of the true twist, whichfact makes the action of the twist thresholds still more pronounced.

It is now evident that although the yarn has the desired twist at theoutlet of the tube 9, in the direction from this outlet toward thestraight portion 13 the yarn has the value of the twist which increasesin front of each twist threshold presented by a successive projection15, which value is in excess of the desired twist. Therefore, by havingthe twist which is greater than the desired value along the straightportion 13, the yarn easily overcomes the twist threshold in the form ofthe end face of the tube 9, projecting into the tube 1.

The rotating portion of the yarn 10 between the tube 9 and the trough 6is pressed by the tension of the yarn to the ribs of the plates 11,these plates intersecting the plane of the trough 6, as it has beenalready described. As the yarn 10 is being delivered in the direction ofthe arrow D, with simultaneous rotation of the abovesaid portion alongthe arrow B, the points A of engagement of the yarn with the plates 11move from the tube 9 toward the periphery of the bowl, i.e. toward thetrough 6, which promotes a motion of the twist toward this trough,whereby the value of the twist adjacent to this trough is greater thanthe desired value. It should also be noted that this displacement of thetwist by the plates 11 helps to overcome the twist threshold presentedby the end face of the tube 9, projecting into the bowl, since the twisthas its smallest value adjacent to this tube 9. The propagation of thetwist over the area from the tube 9 to the trough 6 is also promoted,although to a smaller degree, by the rolling of the yarn 10 over theribs of the plates 11.

Therefore, the yarn 10 has a degree of the twist over the portion fromthe outlet of the tube 9 to the trough 6, which is greater than thedesired twist, this value being at its maximum adjacent to the trough,which yields effective transmission of the twist to the sliver 7 andresults in an increased strength of the abovementioned portion of theyarn.

What is claimed is:

1. An apparatus for ringless spinning of fibre, comprising: a spinningbowl mounted for rotation; means for imparting rotation to said bowl; aninternal inclined surface of said bowl of a frustoconical shape; a lidassociated with said bowl and including a pipe adapted for passage ofseparate fibres therethrough; the base of said bowl having air ventsmade therein for creating suction within said bowl at rotation thereof,to draw said separate fibres from said pipe onto said inclined surface;an annular trough defined within said bowl, adapted to collect thereinsaid separate fibres coming thereinto along said inclined surface and toform said fibres into a sliver at rotation of said bowl; a tube mountedin said lid and adapted to have final yarn, formed from said sliver,delivered therealong; a straight portion of said tube; a portion of saidtube, gradually curving in the direction of the delivery of the yarn;projections provided in said curving portion and adapted to impart atwist to the yarn over said straight portion of said tube, of which thevalue is greater than the desired twist of the yarn, said twist beingtransmitted to said sliver; plates having each one end thereof mountedon said lid and having the opposite, free end thereof projecting intosaid bowl being adapted to engage the yarn, whereby a twist which isgreater than the desired twist of the yarn is transmitted to said sliverbeing formed in said trough.

2. An apparatus as claimed in claim 1, wherein said projections in saidtube are formed by a cylindrical coiled spring having the ends thereofsecured to the opposite end faces of said tube.

3. An apparatus as claimed in claim 1, wherein said plates are arrangedon said lid so that the ends thereof intersect the plane of said trough.

4. An apparatus as claimed in claim 1 wherein said plates are arrangedon said lid so that the point of contact of the yarn with each saidplate moves from the axis of rotation of said bowl toward the peripherythereof in the direction of rotation of said bowl.

5. An apparatus as claimed in claim 4, wherein said plates are shaped asspirals.

1. An apparatus for ringless spinning of fibre, comprising: a spinning bowl mounted for rotation; means for imparting rotation to said bowl; an internal inclined surface of said bowl of a frustoconical shape; a lid associated with said bowl and including a pipe adapted for passage of separate fibres therethrough; the base of said bowl having air vents made therein for creating suction within said bowl at rotation thereof, to draw said separate fibres from said pipe onto said inclined surface; an annular trough defined within said bowl, adapted to collect therein said separate fibres coming thereinto along said inclined surface and to form said fibres into a sliver at rotation of said bowl; a tube mounted in said lid and adapted to have final yarn, formed from said sliver, delivered therealong; a straight portion of said tube; a portion of said tube, gradually curving in the direction of the delivery of the yarn; projections provided in said curving portion and adapted to impart a twist to the yarn over said straight portion of said tube, of which the value is greater than the desired twist of the yarn, said twist being transmitted to said sliver; plates having each one end thereof mounted on said lid and having the opposite, free end thereof projecting into said bowl being adapted to engage the yarn, whereby a twist which is greater than the desired twist of the yarn is transmitted to said sliver being formed in said trough.
 2. An apparatus as claimed in claim 1, wherein said projections in said tube are formed by a cylindrical coiled spring having the ends thereof secured to the opposite end faces of said tube.
 3. An apparatus as claimed in claim 1, wherein said plates are arranged on said lid so that the ends thereof intersect the plane of said trough.
 4. An apparatus as claimed in claim 1 wherein said plates are arranged on said lid so that the point of contact of the yarn with each said plate moves from the axis of rotation of said bowl toward the periphery thereof in the direction of rotation of said bowl.
 5. An apparatus as claimed in claim 4, wherein said plates are shaped as spirals. 